Ensure userspace allocation is 8-byte aligned

This commit is contained in:
Raoul Strackx 2022-03-23 10:03:00 +01:00
parent 531752f39a
commit 6f7d1937e2

View File

@ -2,6 +2,7 @@
use crate::arch::asm;
use crate::cell::UnsafeCell;
use crate::cmp;
use crate::convert::TryInto;
use crate::mem;
use crate::ops::{CoerceUnsized, Deref, DerefMut, Index, IndexMut};
@ -212,7 +213,9 @@ where
unsafe {
// Mustn't call alloc with size 0.
let ptr = if size > 0 {
rtunwrap!(Ok, super::alloc(size, T::align_of())) as _
// `copy_to_userspace` is more efficient when data is 8-byte aligned
let alignment = cmp::max(T::align_of(), 8);
rtunwrap!(Ok, super::alloc(size, alignment)) as _
} else {
T::align_of() as _ // dangling pointer ok for size 0
};